[cato_the_elder]

Well, fertilizers have diminishing returns, you can't keep adding fertilizer to increase the yield as much as you want.

The amount of farmland available globally is limited, so reducing the yields per hectare in one country will probably contribute to food inflation globally.

You could increase the amount of available farmland by deforestation, but that would probably be contrary to the goals of environmental conservatism.

Also, we are assuming a global free market of crops, which is an unrealistic assumption, as there are lots of subsidies and tariffs.